593 heport— 1863. 



age. The types of tliese species in the Smithsonian Museum a^^ ^ "a,^ too im- 

 perfect to determine specifically with any confidence ; and by no means ij. « 

 suitable condition to allow of important conclusions being drawn from them. 

 98. The third article in the Appendix to the same volume of lleports 

 contains a " Catalogue of the llecent Shells, with Descriptions of the I^ew 

 Species," by Dr. A. A. Gould. The specimens were (apparently) in the hands 

 of Dr. Gould for examination when he prepared the MS. for the first Report; 

 and some of them were included in the " Mexican War Collections," B. A, 

 lleport, pp. 227, 228. " The freshwater shells were collected in the Colorado 

 desert and other localities ; the land and marine shells between San Francisco 

 and San Diego." The following is the list of species as determined bj' Dr. 

 Gould, pp. 330-336. The specimens belong to the Smithsonian Institution, 

 where a large portion of them were fortunately discovered and verified. 

 They were collected by W. P. Blake, Esq., and Dr. T. H. Webb. 



Plate. Fig. No. 



1. Osfrea, sp. ind. Parasitic on twigs ; thin, radiately lineated with 



brown. [= O. cmichaohila, C'pr.l Another species, elongated, 

 solid, allied to Viir/imca [var. rtifoidei], San Diego. 



2. Pecten nionotimeris, Conr. San Diego. • 



3. Pecten ventricosus, Shy., +Uijnidus, Sby. [Dead valves, of the 



form ceqttisulcatus.'] San Diego. 



4. My tikis fedulis [ = M. tro^stdus, G\A., antea]. San Francisco. 



5. Modiola capax, Conr. San Diego. 



6. Ventis Ntdtallii, Conr. \_=V. succincta, Val.] San Pedro. 



7. Venus Jlttctif ruga, Sby. San Diego. 



8. Tapes grata, Say<= T. discors, Sby., "=:st?-ammea, Conr."* San 



Pedro. 



XL 19,20. 9. Tapes gracilis, Gld.,n.s. Prel. Eep. 1855. [Quite distinct from 

 every other Tapes known from the coast. It is supposed by 

 Dr. Cooper to be the young of Saxidomus aratm, which in 

 shape and pattern exactly accord with the figure and diagnosis. 

 But the " Tapes'^ is figured without sculpture. The shell was 

 not found at the Smiths. Inst.] San Pedro, Blake. 

 10. Cyclas, sp. ind. Colorado Desert. 



XT. 21,22. \l. Cardiumcruentatmn,G\A.,-i\.B. Prel. Rep. 1855. [P. Z. S. 1856, 

 p. 201, = C. suhstriatum, Conr.] San Diego. [San Pedr..-, 

 Blake, in text.] 



12. Lucina orbella,(jxld. [ = " Mgsia (Sphcerella) fumida/' Conr.] SsJJ 



Pedro. 



13. Lucina Nuttallii, Conr. San Pedro. 



14. Mesodesma ?7-uhrotincta, Sby.f San Pedro. 



15. Tellina vicina, C. B. Ad. [Dead specimens of = Heterodonax 



(" Psammobia," var.) Paci/ica, Conv.^ San Diego. 



16. Tellina sect a, Conr. San Pedro. 



17. Sph(enia\_C'rtfptomya'] Calif ornica, Com:. San Diego. 



18. Petricola carditoides, Conr., =ci/lindracea, Desk. Monterey; San 



Pedro. 



19. Solecurtus Calif orniensis, Conr. San Diego. 



20. Gnathodon Lecontii,Conv.,= G.triff(mi(m, Petit. Colorado Desert. 



[Lecontei is probably the large Texan species : trigonus=meti- 

 dicm is a very distinct shell from Mazatlan.] 



* TsTeither Dr. Gould, nor Conrad himself, in his later geological writings, appears to 

 have called to mind the true T. staminea, to which the Smithsonian shells helong. It is 

 the northern representative of T. grata, but quite distinct : v. synonymy under Venut 

 Petitii—rifjida, pars. 



f- No "Mesodesma" was found among the shells returned to the Smithsonian Institu- 

 tion, nor has any been heard-ot from the coast. Dr. Gould's shell maj have been Semelt 

 pulchra, which was in the collection. 



78 



